Isolation, identification and immunosuppressive activity of SDZ-IMM-125 metabolites from human liver microsomes.
 

Dieden R, Verbeeck RK, Latinne D, Wallemacq P, Maton N, Lhoest GJ
 

Department of Pharmaceutical Sciences-UCL, Pharmacokinetics and Metabolism Unit-FATC Laboratory of Mass Spectrometry, Brussels, Belgium.
 

SDZ-IMM-125 N-methyl leucine 9 hydroxylated in the gamma position is a metabolite which was extracted from incubated human liver microsomes and subsequently separated by normal and reverse-phase HPLC. This metabolite was identified by fast atom bombardment mass spectrometry, electrospray-ms/ms mass spectrometry and nuclear magnetic resonance spectroscopy. The in vitro 50% inhibitory concentration, tested against bidirectional mixed lymphocyte reaction was 80 microg/l indicating that this metabolite does not retain in vitro immunosuppressive activity most probably due to the structural modification of SDZ-IMM-125 in the recognized binding region to cyclophilin A reducing its binding affinity relative to the parent drug.
 

PMID: 10412896, UI: 99339241